Abstract: A two-speed transmission including: a sun gear configured to be rotated by an external driving force; a planet gear arranged around the sun gear; a ring gear having a gear train; a first clutch configured to be engaged with the sun gear to be restrained by the sun gear if the sun gear is rotated in a first direction; a second clutch configured to be engaged with the ring gear to be restrained by the ring gear if the sun gear is rotated in a second direction; and a carrier configured to receive a driving force from the sun gear by restraint of the first clutch to be driven in a first reduction gear ratio or to receive a driving force that is transferred through the sun gear, the planet gear, and ring gear by restraint of the second clutch to be driven in a second reduction gear ratio.

Abstract: A housing structure for geared motors is disclosed. The housing structure is designed to seal the spaces between a stator core and first and second housings to prevent infiltration of moisture and impurities to a motor's drive part through the spaces or formation and growth of ice on the drive part, thus the motor always being smoothly started in its operation, without having a high drive torque undesirably increased to remove ice or impurities from the drive part. The first housing has a support part functioning to rotatably support a first end of the rotating shaft on the stator core, while the second housing has a cup part functioning to rotatably support a second end of the rotating shaft on the stator core. The support part of the first housing includes a first spherical bearing, a first seat part, and a bearing seat. The first housing also has a cylindrical part assembled with the stator core, and a shaft hole rotatably supporting an output shaft of the motor.